The main goal of this project is to implement and evaluate an intervention that will improve, maintain and diffuse early cancer detection protocols among primary care physicians. The target population consists of physicians who have mostly low-to-moderate-income black and, to a less extent, Hispanic patients. Four body sites are targeted: breast, cervix, colon, rectum, and oral cavity. The intervention is a multistrategy approach. Our main research hypothesis is that intervention through the HMO in this study can legitimate practices that physicians already accept as efficacious. Therefore, endorsement by the HMO of early detection screening procedures and verification through the existing quality assurance program will encourage increased use of the guidelines. Our second hypothesis is that once these procedures are adopted, they will become institutionalized as part of the physician practice patterns at these study sites and will be offered to all patients regardless of membership in the HMO. To test these two hypotheses we intend to: 1. Determine baseline screening rates; 2. Develop screening and early detection procedures with the HMO staff and intervention physicians as part of the quality assurance process; 3. Implement procedures through the HMO by which application of the guidelines can be monitored and periodically communicated to the intervention physicians; 4. Conduct chart reviews before, during, and after the intervention to assess the proportion of patients screened according to the guidelines; 5. Monitor patient charts at both the intervention and control sites to assess the extent of diffusion to non-HMO patients; and 6. Establish an evaluation design that will test the hypotheses. A second goal of the study is to systematically observe, document, and report the process of program dissemination among these primary care physicians.